Caring for landscape plants in winter
-Establishing (was planted less than 2 years ago) plant material needs watering once or twice a month during the winter.
-Water when temperatures are above 40 degrees F and there is no snow on the ground.
Your winter watering schedule should start once you turn off your irrigation system or, if you don’t have an irrigation system, once deciduous plants have gone dormant for the winter. It is imperative that you water your trees, especially evergreens, and plants through the winter. For general watering guidelines and how-to, read our Plant Care Guide.
A lack of winter water can result in significant branch die-back and slow the process of roots establishing. Severe lack of water through the winter can even kill your plants.
Most deciduous trees and shrubs will turn a number of shades of yellow, orange, red, and eventually brown and lose all their leaves before becoming dormant for the winter. Ornamental grasses will turn golden, brown, and straw colored but leave you with beautiful shows of plumes all through winter while they are dormant. Perennials will most likely die back to the ground. For ornamental grasses and perennials, it’s best to leave this foliage, even though it’s dead, as it resupplies nutrients to the ground as foliage decomposes. Once you have seen the signs of winter dormancy, you can back off on watering to only once or twice a month. Until then, keep an eye on soil moisture and water as necessary.
Tree-Wrap & Mulch
Young trees have thin, smooth bark which can get burned by the winter sun. This stresses the tree and makes it difficult for the tree to move nutrients and water up through the trunk toward the canopy. To protect from winter sun-scalding, use tree wrap on any trees less than 4” in diameter. We suggest as a general rule of thumb to wrap trees from Halloween through Easter. Pick up some tree wrap at Silver Sage today!
Protect shrubs and perennials with a thicker layer of mulch around the base of the plants. This helps retain moisture and insulate roots.
Root Stimulator: One last time
If you’re using root stimulator, make one more application – as long as the plants have green leaves on them. Resume using root stimulator next spring once buds have started to push out.
Pruning: Now is not the time
In many cases, late winter or early spring, right after cold weather and just before bud break (while plants are still dormant), is the best time to prune plants. This includes: Barberry, Butterfly bush, Blue Spireas (Caryopteris), Smokebush, Rose of Sharon, smooth or panicle hydrangeas, Hybrid tea roses, Elderberry, Snowberry, American Cranberry Bush.
Plants that should not be pruned while dormant include: Lilacs, Serviceberry, Chokeberry, Flowering Quince, Flowering Dogwood, Daphne, Forsythia, once-blooming roses, flowering currant, Korean Spice Viburnum, Weigelia. These plants make their flower buds for the next year during late summer and should be pruned right after blooms fade.
Snow can be useful in providing moisture and even protecting short plants from the elements. If you are shoveling snow, plants may benefit from the extra moisture by piling snow on top or around the base. Be sure you’re not shoveling snow-melting salts and chemicals onto your plants unless you have used plant and pet safe products.
Preparing for Spring
Add valuable nutrients back to your soil and save landfill space at the same time by composting your twigs, branches, leaves, and grass clippings to be used next year in your Spring garden. Composted yard material can be used as a soil amendment and/or mulch and can help improve and aerate your heavy clay, alkaline, Colorado soil.
Check out this CSU Extension fact sheet on Composting Yard Waste
Fall is the best time to fertilize your bluegrass or cool weather turf lawn with nitrogen. Check out these CSU Extension guidelines for doing it right. If you’re under drought restrictions, read up on Fall lawn fertilization: during drought.